AB0841 CONCORDANCE AND PROGNOSTIC RELEVANCE OF DIFFERENT DEFINITIONS OF SYSTEMIC SCLEROSIS INTERSTITIAL LUNG DISEASE PROGRESSION
Authors: E. De Lorenzis, G. Natalello, S. Di Donato, L. Verardi, P. G. Cerasuolo, V. Kakkar, M. A. D’agostino, F. Del Galdo, S. L. Bosello
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Interstitial lung disease (ILD) is a common complication of systemic sclerosis (SSc) with a variable natural history and prognosis. Several definitions of SSc-ILD progression have been proposed including minimal clinical important worsening of forced vital capacity (FVC MCIW), EUropean Scleroderma Trials and Research group (EUSTAR) progression, Outcome Measures in Rheumatology Clinical Trials (OMERACT) progression, and Erice ILD working group progression. The aim of the study was to assess concordance and prognostic value of these different definitions in SSc-ILD patients overall and specific clinical subsets. <h3>Objectives</h3> Progression status was assessed in consecutive SSc-ILD patients over a period of 24 months and the mortality related to SSc-ILD was compared between progressors and non-progressors according to different definitions in the subsequent 60 months. Severe baseline pulmonary functional impairment was defined for a combination of FVC&lt;80% and alveolar diffusion of CO (DLco) &lt;60% of predicted. <h3>Methods</h3> Progression status was assessed in consecutive SSc-ILD patients over a period of 24 months and the mortality related to SSc-ILD was compared between progressors and non-progressors according to different definitions in the subsequent 60 months. Severe baseline pulmonary functional impairment was defined for a combination of FVC&lt;80% and alveolar diffusion of CO (DLco) &lt;60% of predicted. <h3>Results</h3> The retrospective analysis included 245 SSc-ILD patients (age 54.6±13.2 years, male 18.8%) with a 54.7% prevalence od diffuse cutaneous variant and a median disease duration of 4 years (IQR 2-8). Disease duration ≤ 3 years, severe pulmonary functional impairment, and pulmonary artery systolic pressure (PASP) 40 mmHg were reported in the 47.8%, 18.0% and 17.1% of patients, respectively. Twenty-six deaths were reported among enrolled patients and progression according to FVC MCIW (HR 2.27, 95% IC 1.03 - 4.97, p=0.041), OMERACT (HR 2.90, 95% IC 1.28 - 6.57, p=0.011), and Erice criteria (HR 11.02, 95% IC 2.38 - 51.08, p=0.002) were associated with mortality in the whole cohort. Prognosis prediction, considering the 4 different definitions of progression status, was challenging (independently from the adopted criteria) in patients with disease duration &gt;3 years, mild pulmonary function test impairment, and PASP ≥40 mmHg. Erice criteria performed better in patients with disease duration ≤3 years, limited cutaneous variant, and PASP &lt;40 mmHg, while OMERACT criteria in patients with diffuse cutaneous variant, and severe baseline pulmonary functional impairment. <h3>Conclusion</h3> The proposed progression definitions of SSc-ILD are not interchangeable, since up to one third of progressors could be misdiagnosed using different criteria. Regardless of the criteria used, progressor patients presented more frequently a diffuse skin variant of the disease, a shorter disease duration and worse baseline functional impairment of the lung. <h3>REFERENCES:</h3> NIL. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.